It’s the Beginning of the End for Cassini (But the Pictures Will Be Awesome)

A view of Saturn’s north pole captured by Cassini’s wide-angle camera on Dec. 3, 2016. (NASA/JPL-Caltech/SSI)

After more than twelve years in orbit around Saturn, NASA’s Cassini spacecraft is now in its final year of operation…and newly-positioned in an orbit that will send it soaring high over the planet’s north pole as well as close by the outer edge of its glorious shining rings.

Over the course of 20 week-long “ring-grazing orbits” — the first of which was completed on Dec. 4 — Cassini will obtain close-up images and data on the composition and structure of Saturn’s rings and nearby shepherd moons.

It’s the mission’s penultimate phase, heralding the end of Cassini in September 2017.

“This is it, the beginning of the end of our historic exploration of Saturn,” said Cassini imaging team leader Carolyn Porco. “Let these images — and those to come — remind you that we’ve lived a bold and daring adventure around the solar system’s most magnificent planet.”

This graphic shows the closest approaches of Cassini’s final two orbital phases. Ring-grazing orbits are shown in gray; Grand Finale orbits are shown in blue. The orange line shows the spacecraft’s Sept. 2017 final plunge into Saturn. (Credit: NASA/JPL-Caltech)

Cassini’s ring-grazing orbits will take it about 6,800 miles from the outer edge of the ropy F ring at closest pass and then high above the planet’s north pole, seen above in an image obtained just before the first close approach on Dec. 3, 2016.

“It’s taken years of planning, but now that we’re finally here, the whole Cassini team is excited to begin studying the data that come from these ring-grazing orbits,” said Linda Spilker, Cassini project scientist at JPL in Pasadena, CA. “This is a remarkable time in what’s already been a thrilling journey.”

Saturn’s north polar cyclone, imaged by Cassini in 2012 (NASA/JPL/SSI)

On April 22 Cassini will complete its final ring-grazing pass and, using the gravity of Titan, move into its final “Grand Finale” series of orbits that will take it between the rings and Saturn’s cloud tops — the closest any spacecraft has ever come to Saturn.

Just five months later on Sept. 15, 2017, at 8:07 a.m. EDT, Cassini will make its final pass around Saturn, diving into its atmosphere and transmitting data back to Earth for as long as it can before finally succumbing to the stresses of entry.

While the thought of the end of the Cassini mission and the destruction of the spacecraft is enough to give me chills, I —and I know I’m not alone here — eagerly await the unprecedented views of Saturn that will accompany these final phases of this incredibly successful and inspirational mission.

Launched in 1997, Cassini has been touring the Saturn system since arriving there in 2004 for an up-close study of the planet, its rings and moons. During its journey, Cassini has made numerous dramatic discoveries, including a global ocean with indications of hydrothermal activity within the moon Enceladus, and liquid methane seas on another moon, Titan.